1. Field of the Invention
The present invention relates to any field that could benefit from a more powerful and more visible laser that has improved range. One specific field is the field of emergency search and rescue lights for use by imperiled individuals who are lost, and specifically to emergency rescue lights utilizing laser technology for enhancing visual detection by search and rescue (SAR) personnel in aircraft or marine vessels searching for an imperiled individual using the rescue light. The present invention provides an improved laser system that has increased power, visibility, and range, beyond what is presently in existence today for a particular class of laser. More specifically, a laser system in which the result is increased power, visibility, and range, without having laser radiation in excess of the accessible emission limits stated in 21 CFR Part 1040.10 for a particular class laser (e.g. a more powerful class I laser or a more powerful class IIIa laser).
2. Description of Related Art
Portable emergency rescue lights used by an imperiled person trying to be found typically utilize incandescent or strobe lights for visual detection and recognition by searching airborne or marine personnel. The illumination intensity of incandescent lights used in emergency signaling lights is often limited in time, range, and available power and can often be inadequate for detection and signaling purposes. Strobe lights can have a greater visual detection and illumination range than incandescent lights but also have intensity limits. Strobe lights are pulsed and not a steady beam of light. Strobe lights can often have a night blinding effect on the user and rescue personnel.
The light bulb power consumption and the amount of battery power available in a portable survival light limits the amount of xe2x80x9conxe2x80x9d time and available watts in a survival scenario. The amount of battery time available for illumination can be a critical variable in a survival situation.
The present invention provides an improved portable, battery-powered survival light that does not employ either strobe or incandescent bulbs but instead uses a laser light source and laser generator. Advantages of laser light are beam focus, high light intensity and low power consumption. These advantages enable a laser light beam to be continuously visible at great distances for greater time periods. One drawback of using a class IIIa laser light in a search and rescue scenario is that the laser beam of light is so small that at long range, the visible beam area is small and must pinpoint the rescue aircraft or searching vessel; otherwise the laser light will not be seen by the searching personnel. A line generating lens may be used but the loss in intensity is too great. Another perceived drawback of the use of laser light is potential eye damage to users. U.S. Government regulations limit the maximum watt emission level of over-the-counter laser light products, which ensures a level of radiation below the accessible emission limits for a class IIIa laser.
The present invention provides a survival light of high intensity, low power consumption, and improved range visibility that complies with U.S. Government safety regulations for over-the-counter sales.
An emergency rescue light utilizing a plurality of laser light generators contained within a waterproof housing. The signal light includes multiple laser light generators, batteries, and a light circuit all of which are enclosed and sealed within a waterproof housing having a lens which allows light emitted from the enclosed laser light generators to pass through to the outside. In the preferred embodiment, off-the-shelf laser light beam generators that meet U.S. Government regulation for safety are used. For human optical safety reasons each laser light beam source cannot exceed the accessible emission limits contained in CFR 21 Part 1040.10 class IIIa laser(5 milliwatts in power).
Multiple laser light generators are mounted together and aligned substantially parallel to radiate individual light beams, all in substantially the same direction to form a laser array. The pattern generated by the laser array can be tightened (less space between beams) by the use of a prism, mirror or lens. Each of two laser light generators or more can be slightly angled towards the other so that the laser light beams emitted converge at a point at a fixed distance away from the laser array source (line of sight to the horizon) so that maximum combined total light energy is produced at a desired range, while not combining early enough to exceed the accessible emission limits for a specific class laser (e.g. one class IIIa laser). One or more lenses or reflective surfaces may also be used to spread the beam vertically, usually called a line-generating device. These techniques may be combined for maximizing the visibility of the laser signal to a distant person.
The laser arrays are enclosed by a waterproof housing that incorporates one or more transparent lenses, prisms, or mirrors. The multiple laser light beams emitted from the laser array are directed outwardly through one or more lenses, mirrors or prisms, which can provide optical convergence or divergence of the laser light beams producing desirable intensity patterns at a prescribed distance, such as line-of-sight (LOS) to the estimated horizon.
One or more batteries sufficient to energize the laser array are electrically connected and mounted within the housing. A power control circuit incorporating an on/off switch connects the laser light beam generators and batteries so that the laser light beam generators in the laser array may be energized by closing the switch.
In the preferred embodiment the waterproof housing includes a rigid base and a laser light support platform. The base is elongated, square and open at the top end. The light platform closes the open end of the base. The light platform incorporates a freely rotatable array cylinder attached to a mount head which contains a mirror and lens, that rotates 360xc2x0 . The mirror is angled relative to the base so that laser light beams emitted from the laser array contained within the base are reflected to pass through the lens. A motor mounted within the base rotates the cylinder from within. The rotation allows the laser light beams reflected by the mirror to be projected 360 degrees horizontally so that the signaling/detecting light produced covers 360 degrees of the surrounding horizon when directed parallel to the ocean surface.
The light array control circuit is also connected to the rotating motor so that when the laser array is energized, the motor is also energized. The base encloses the motor, batteries and power control circuit and is sealed at the top end by the attachment of the light platform.
The entire waterproof light assembly may be mounted within a portable, handheld, two degree of freedom leveling gimbal. The housing is pivotally attached to an inner gimbal which is mounted within an outer gimbal so that the light assembly housing is maintained by gravity in a level horizontal position when held by the user or mounted on a vessel. A handle is attached to the outer gimbal to facilitate the operation of the signal light by one person. The motor rotates the cylinder effectively projecting the signaling light produced in a 360xc2x0 horizontal pattern for maximum surface visibility.
In an emergency situation in the ocean, the user would typically be in a raft and would turn on the power switch and grasp the gimbal handle to allow the laser beam array to rotate parallel to the earth""s surface for 360xc2x0 rotation, covering the entire horizon. The gimbals keep the light array horizontal regardless of raft motion. The user could manually grasp the entire housing to override the gimbal and direct the light beam in a specific direction. Preferably, individually emitted laser light beams are each aligned relative to each other to converge roughly on the observable horizon relative to the user in the raft about eight miles from the user source (line of sight) for optimum light energy area distribution and sighting. The gimbals could include an engageable lock to permit manual manipulation of the device to aim the light array manually at a non-horizontal angle.
In an alternate embodiment of the invention, the laser light array is mounted within a flashlight housing formed by an elongated cylindrical body and a projection lens mounted head at one end. The elongated cylindrical body houses the batteries, power switch, and light circuit. A laser array of two or more laser light beam generators is housed and contained within the housing adjacent the lens head, transmitting light emitted from the laser generators to pass through the lens. Laser light beams emitted from the laser array are aligned, possibly using prisms, lenses or mirrors to project outwards through the lens substantially along a plurality of parallel axes distributed in a clustered pattern and through a lens for spreading the beam vertically, allowing the sweeping of the horizon with the signal.
The light beams emitted from the laser array may be parallel or may be individually angled relative to the optical array axis when passing through the transparent lens for controlling the total light energy in a greater area at a prescribed distance from the light source. The arrangement of the laser light beam generators may be adjusted to form a specific pattern. The lens can cause the multiple laser beams mounted parallel to each other to slightly converge or to diverge to cover a wider area at a distance from the source. From a low position above the earth""s surface, such as a raft or small boat, the line-of-sight horizon is approximately 6 to 8 miles. The multiple light beams can be caused to diverge slightly so that at the LOS horizon, a larger area of the beams is observed. Conversely, the beams can be made to converge slightly for maximum light energy at the LOS horizon, but reduced beam area.
In yet another embodiment of the invention the laser light beams emitted from the laser array are each manipulated by a prism so that the laser light beams are aligned along a straight reference plane. The laser light sources are affixed together in a defined geometrical pattern, such as two rows of six lights each, and when used in conjunction with an optic lens, the resultant total beam can be controlled and oriented as to the width of the beam, the fantail or spread distance of the beam, and the spatial relationship of the individual light sources.
It is an object of this invention to provide an emergency rescue light that utilizes multiple laser light sources mounted together in a laser array to produce a rescue signal light easily detectable at great distances from the source while in compliance with U.S. Government regulations.
In accordance with these and other objects which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.